I used to buy cheap 30-40 dollar filters from Hoya and Quanterray (sp?)... thinking I would never be able to notice a difference between that and a higher end UV filter.

Then I had some extra cash and decided to get a top of the line B+W filter (over $100) and boy... was I wrong! I could definitely see a difference between the inexpensive and expensive filter. The B+W was much more vibrant. No more cheapo's for me.